Tape with weakened edge



March 1955 c. w. VOGT 2,703,764

TAPE'WITH WEAKENED EDGE Filed Nov. 2, 1951 FIG. I. FIG. 2.

IN VEN TOR. CLARENCE W. VOGT United States Patent TAPE WITH WEAKENEDEDGE Clarence W. Vogt, Norwalk, Conn.

Application November 2, 1951, Serial No. 254,535

2 Claims. (Cl. 117-37) The present invention relates to tapes formed ofsynthetic plastic film and embodies an improved form of tape havingmeans formed therein to facilitate transverse tearing or rupturingthereof. The relatively great resistance to tear in directions acrossthe grain of tapes of this character is well known and, in many uses, acharacteristic of great value. However, in someinstances, this propertybecomes a disadvantage and renders the tape unsuitable for use.

Examples of tapes of this type are tapes formed of cellulose derivatives(e. g. regenerated cellulose, and cellulose esters and ethers) and ofsynthetic resins such as polyvinyl resins, polyethylene and polyacrylicesters. They are now widely used, and their properties well known. Inaccordance with the present invention, it is proposed to provide tapesof the above character with structural characteristics such that,without appreciably impairing their tensile strength, they may be easllytorn by exerting suitable stresses thereon at one or both edges thereof.

To realize the foregoing object, such synthetic plastic film tapes areformed along one or both edges thereof with structure of a relativelyweak nature by means of which tearing will take place with theapplication of relatively little tearing stress. This may beaccomplished by embrittling one or both edges of the tape by applyingheat thereto, thus causing such edge or edges to have relatively lowresistance to tearing stresses.

In order that the invention may be better understood, it will bedescribed in connection with one specific use thereof and, to that end,reference will be made to the accompanying drawings, wherein Figure 1 isa partial plan view showing a tape formed in accordance with the presentinvention;

Figure 2 is a view similar to Figure 1, showing a modified form of tapeand in which both edges of the tape are embrittled;

Figure 3 is a perspective view showing a plurality of commoditiesconnected together by means of tapes formed in accordance with thepresent invention;

Figure 4 is a perspective view similar to Figure 3, but showing themanner in which the top pair of commodities is removed from theassembled group illustrated in Figure 3; and

Figure 5 is a perspective view showing a modified way by means of whichthe commodities may be removed in accordance with the present invention.

Referring to the above drawings, a synthetic plastic tape is illustratedat as being provided at the edge 11 thereof with an embrittled portion12 in order to facilitate the transverse tearing or rupturing of thetape. The embrittlement of the edge portion 12 may be accomplished bysubjecting that portion of the tape to an elevated temperature, suchtemperature being below that temperature at which the structure ofthetape is destroyed. It may also be preferable to utilize a temperaturesuch that discoloration of the tape is avoided. Depending upon thenature of the material, a temperature in the range of about 350 F. to400 F. produces suitable embrittlement, the particular temperature,however, being dependent upon the extent of embrittlement desired. Also,temperatures outside of this range may be used if the nature of thematerial so requires.

If desired, the embrittlement of the tape may be achieved after theadhesive coating is applied to one side thereof, in which event theelevated temperature utilized 2,703,764 Patented Mar. 8, 1955 See forembrittling the edge portion of the tape also renders inactive theadhesive coating. As a result, that portion of the tape is not tightlyadhered to the object to which the tape is applied, and the starting ofthe tear of the tape transversely of its length is greatly facilitated.

In the form of the invention shown in Figure 2, the tape 10 is shown asbeing embrittled not only adjacent the side 11, but at the side 13thereof in the region indicated at 14. in this form of the invention,the tearing of the tape from either side may be readily started.

Tapes formed with the weakened edge portions hereinabove described areparticularly useful in assembling articles and commodities, asillustrated in Figures 3, 4, and 5. In Figures 3 and 4, for example, aplurality of commodities 15, 16, 17, 18, 19 and 20 are assembledtogether in pairs and in stacked relationship. End tapes 21 and 22 serveto connect together each of the respective pairs 15, 16, 17, 18, and 19,20. In the stacked relationship illustrated in Figure 3, band tapes 23serve to maintain all of the pairs effectively as a rigid unit. Ifdesired, spots of any suitable translucent adhesive material 25 may beprovided at the meeting edges of one or more of the respective pairs 15,16, 17, 18 and 19, 20 in order to anchor the respective pairs moreeffectively in the assembled position illustrated in Figure 3.

To remove one or more of the pairs from the unit illustrated in Figure3, for example the upper pair, it is only necessary to twist such pairin either direction (counter-clockwise as illustrated in Figure 4) tocause the tape 23 to tear at the meeting edges of the pairs to beseparated and, if adhesive 25 is utilized between adjacent pairs, torupture such adhesive. The weakened portions in the tape 23 formed bythe embrittled portions, as hereinabove described, permits separation ofthe pairs, as above described, with great ease, whereas if the tape 23had not been formed with the weakened portions, it would be extremelydifficult to separate the pairs by the twisting operation abovedescribed.

After one or more pairs have been separated from the multiple unit,individual elements may be separated from each other by splitting apartthe bonds formed by the tapes 21, 22. This is readily done by swingingthe articles away from each other about an axis coincidental with theadjacent corner edges of two adjacent articles at a side thereofadjacent embrittled edges of the tapes. Here again the embrittledportions formed in the tapes facilitate such separation.

In the form shown in Figure 5, the tapes of the present invention areutilized to secure a plurality of commodities 26, 27, 23, and 29together, end tapes 30 and 31 (of the form of tape shown in Figure 1)being utilized for this purpose. The articles assembled into the unitarystructure of Figure 5 are separated from each other by twisting thearticles with respect to each other in the meeting planes of thearticles to be separated in order to sever the side tape 32 adjacent theplane of the contiguous sides of the articles being separated. In viewof the fact that the upper edge only (as seen in Figure 5) of the tapeshas been embrittled in order to separate the articles from adjacentarticles, it is necessary to swing them outwardly and downwardly toutilize the weakened edge of the tape to facilitate starting of thetear.

From the foregoing it will be seen that a tape of synthetic plastic filmmaterial has been provided having the Well known tensile strengthinherent in such material, but at the same time having suitably formedweakened portions along one or more edges to facilitate tearing of thetape at a multiplicity of points. The tape may consist of any structurehaving in substantial degree the properties above mentioned. Forexample, any plastic film or film having one or more coatings orlaminations of other or similar materials may be utilized in accordancewith this invention. Moreover, if desired, one or both edges of the tapemay be further weakened by forming therein cuts or serrations such asillustrated in my co-pending application Serial No. 241,047, filedAugust 9, 1951, for Synthetic Plastic Film Tape, wherein a relativelywide band of material is slit into a plurality of tapes. In such anoperation, of course, heating mechanism would be utilized eitherdirectly with the slitting mechanism or before or after the slittingoperation, the

heating mechanism being adapted to form the embrittled areas on thetapes as hereinabove described. As above mentioned, Where embrittlementis accomplished after the adhesive is applied, additional advantagesaccrue because of the possibility of impairing the effectiveness of theadhesive immediately beneath the embrittled areas, thus facilitating thestarting of a desired tear as above mentioned.

While the invention has been described with specific reference to theaccompanying drawings, it is not to be limited save as defined in theappended claims.

I claim:

1. An adhesive tape formed of a fiberless plastic film material having arelatively high tear strength transversely and longitudinally, said tapehaving narrow longitudinally extending edge portions extendingthroughout the entire length of the tape, said edge portions beingweakened substantially continuously throughout their entire length toreduce their resistance to transverse tearing, the remainder of saidtape being essentially unimpaired in strength between said edgeportions, and a layer of adhesive on one side of said tape, the adhesivebeing unimpaired in strength between said edge portions, the edgeportions being relatively non-adhesive to reduce the tendency of theedge portions to adhere to each other when the tape is coiled.

2. An adhesive tape formed of a cellulose plastic film material having arelatively high tear strength transversely and longitudinally, said tapehaving narrow longitudinally extending edge portions extendingthroughout the entire length of the tape, said edge portions embrittledby heating to weaken said edge portions substantially continuouslythroughout their entire length to reduce their resistance to transversetearing, and a layer of adhesive on one side of said tape, the adhesivebeing unimpaired in strength between said edge portions, the edgeportions being relatively non-adhesive to reduce the tendency of theedge portions to adhere to each other when the tape is coiled.

References Cited in the file of this patent UNITED STATES PATENTS2,008,659 Salfisberg July 16, 1935 2,047,982 Page July 21, 19362,240,274 Wade Apr. 29, 1941 2,281,635 Strauss May 5, 1942 2,358,246Nicolle Sept. 12, 1944 2,377,118 Weisrnan May 29, 1945 2,460,566 Brownet al. Feb. 1, 1949 2,462,977 Kitchin et al. Mar. 1, 1949 2,508,855Brown May 23, 1950 2,531,631 Jordan Nov. 28, 1950 2,576,826 Dobbs et al.Nov. 27, 1951

1. AN ADHESIVE TAPE FORMED OF A FIBERLESS PLASTIC FILM MATERIAL HAVING ARELATIVELY HIGH TEAR STRENGTH TANSVERSELY AND LONGITUDINALLY, SAID TAPEHAVING NARROW LONGITUDINALLY EXTENDING EDGE PORTIONS EXTENDINGTHROUGHOUT THE ENTIRE LENGTH OF THE TAPE, SAID EDGE PORTIONS BEINGWEAKENED SUBSTANTIALLY CONTINUOUSLY THROUGHOUT THEIR ENTIRE LENGTH TOREDUCE THEIR RESISTANCE TO TRANSVERSE TEARING, THE REMAINDER OF SAIDTAPE BEING ESSENTIALLY UNIMPAIRED IN STRENGTH BETWEEN SAID EDGEPORTIONS, AND A LAYER ADHESIVE ON ONE SIDE OF SAID TAPE, THE ADHESIVEBEING UNIMPAIRED IN STRENGTH BETWEEN SAID EDGE PORTIONS, THE EDGEPORTIONS BEING RELATIVELY NON-ADHESIVE TO REDUCE THE TENDENCY OF THEEDGE PORTIONS TO ADHERE TO EACH OTHER WHEN THE TAPE IS COILED.